Wireless Body Area Network (WBAN), as a branch of wireless communication, consists of nodes distributed on a surface of a human body or inside a human body and a personal terminal. By the WBAN, the human body can communicate with external electronic equipment such as a mobile phone, and information of the human body can further be finally sent to a destination such as a hospital by virtue of another network such as a Wireless Fidelity (WIFI) network and a 3rd-Generation (3G) network. The WBAN may be applied to many fields such as recreational activities, physical activities and the military field, but what motivates the rise of the WBAN most is its application to the field of medical services. Along with the improvement of the living standard of people and more pursuits of health, application of the WBAN to the field of medical services will be widely developed.
In the field of medical services, a WBAN provides a method for monitoring a health condition of a human body for a long time under without causing any influence to normal life of people. Since nodes are located on a human body and some nodes such as a blood pressure information acquisition node are even required to be implanted into the human body, there are many requirements raised on the WBAN. First, the nodes in the WBAN are required to be small in size, light in weight and easy for the human body to wear. Second, since the nodes are required to work for a long time, the power consumption of the nodes is required to be as low as possible.
Energy of a node is mainly consumed to the communication between the node and a personal terminal, so that it is very necessary and practically significant to propose a low-power-consumption Media Access Control (MAC) layer protocol.
In a related technology, an efficient MAC layer protocol for the WBAN is proposed. This protocol proposes two efficient methods: flexible timeslot allocation and reduction in the number of switching times of wireless receiving and sending. In addition, a MAC method for a WBAN is also proposed in the related technology. This method has the following characteristics: a node is made to enter a sleep mode more frequently; and communication robustness is enhanced.
The Institute of Electrical and Electronic Engineers (IEEE) proposes a WBAN protocol. FIG. 1 is a schematic diagram of a frame structure specified in the WBAN protocol in IEEE according to the related technology. The structure of the WBAN frame, shown in FIG. 1, has some shortcomings. First, Random Access Period (RAP) is an ordinary service, but adopts a Carrier Sense Multiple Access with Collision Avoidance (CAMS/CA) access manner. Since most of nodes periodically acquire physical sign information of a human body, traffic of respective nodes is relatively stable, which makes adoption of CSMA/CA questionable. Second, in IEEE, if a node fails to access a channel in Exclusive Access Phase (EAP) and RAP or the node still has a service, a Management Access Phase (MAP) may also be adopted for sending. MAP runs in Scheduling and Polling manners. The Polling manner can achieve collision avoidance. However, MAP requires a Hub and the node (e.g, sensor) to perform a series of “queries-responses”, and such as process causes additional interaction consumption. Moreover, Polling is performed according to a certain sequence, when the Hub polls a certain node, if this node makes an application to the Hub for a relatively longer timeslot resource through an Acknowledgement (ACK) response, and those nodes which have not yet been polled may apply for relatively fewer timeslots (because the length of MAP is fixed), so that fairness may not be guaranteed. Third, in IEEE, a beacon frame 2 (Beacon2, which is B2 in the figure) only serves to mark a beginning of a Contention Access Phase (CAP), and the function of the beacon frame 2 may further be developed.
For a problem existing in a signaling transmission structure of a WBAN in the related technology, there is yet no effective solution.